Studies on the Pathogenicity of Pebrine Spores Isolated from Ichneumon Fly (Xanthopimpla Pedator) Infesting Tropical Tasar Silkworm on Healthy Silkworm Larvae

Abstract

Tasar culture is the livelihood of the majority of poor tribal peoples of central and north eastern India. The tasar culture is being practiced in the outdoor condition it is amenable to different pests and predators which also harbors the tasar silkworm infecting diseases causing pathogens such as pebrine disease. The present study was aimed at isolating and purifying the pebrine spores from Ichneumon fly infesting tasar silkworm. The purified spores were artificially inoculated to healthy tasar silkworm larvae per orally. The observation of pebrine spores in inoculated larvae showed the presence of pebrine spores after 16 days post inoculation (dpi). The inoculated larvae showed typical symptoms of pebrine in tropical tasar silkworm i.e., appearance of black pepper spots on the larval integument which were distributed sparsely. The result confirms that, pebrine disease can be transmitted by the Ichneumon fly carrying the pebrine spores. This also confirms that, Ichneumon fly can be secondary source of pebrine contamination in the tasar rearing fields.